Recently, two-wheel wheelchair gains a lot of attention since it has high mobility better than conventional four-wheel wheelchair. Two-wheel wheelchair consists of two actuated wheels and it is similar with wheel inverted pendulum. Therefore, stabilization control is utilized to sustain the human posture with safety. In this research, the motion of two-wheel wheelchair on the slope is considered. Repulsive compliance control with Reaction Torque Observer (RTOB) is conducted in order to determine the optimal pitch angle command for going up and down the slope. Furthermore, parameter determination of repulsive compliance control is analyzed and appropriate parameter for the motion on the slope can be determined. Simulation and experimental results show the validity of proposed command generation.